Technology for producing a three-dimensional model in a target space has been so far proposed by Document 1 (JP Pub. No. 1992-133184), for example. The technology described in Document 1 projects lattice light on a target space to capture a projection image, thereby finding a position and an inclination of each plane based on positional relation of intersection points of a lattice in the projection image.
In Document 1, structure lines in a room is calculated by classifying each adjacent relation of planes into a fold, a ramp boundary or in-plane boundary based on positions and inclinations of planes and then calculating plane boundaries to obtain intersection lines. That is, a configuration described in Document 1 extracts folds, ramp boundaries and in-plane boundaries in order to extract structure lines in the room including objects disposed in the target space.
Document 1 also describes restoration of structure lines, which are obstructed by a small object(s) and cannot be detected from the image for extracting the structure lines in this way.
Measurements may require removing an interior object(s) when interior wallpapers are changed to new ones or when heat insulators are installed.
Document 1 discloses that structure lines can be stably restored even when a region lacks part thereof owing to noise, a small obstacle(s) or the like. The technology described in Document 1 cannot however produce a model of three-dimensional structure after an interior object(s) is(are) removed in order to change interior wallpapers or install heat insulators because the technology described in Document 1 extracts a large object such as a desk as a component of a three-dimensional model.